NAME

csv2 - Description of the csv2 zone file that MaraDNS uses

DESCRIPTION

The csv2 zone file format is MaraDNS' standard zone file format. This
zone file format uses any kind of whitespace (space, tab, and carriage
return), or the '|' character, to delimit fields.
Tildedelimitation
In newer MaraDNS releases, the tilde ('~') character is used to delimit
records in csv2 zone files; in order to maintain maximum compatibility
with older MaraDNS zone files, this feature is only enabled if a tilde
is placed between the first and second record. Otherwise, tildes are
not allowed in zone files (except in comments).
Most older MaraDNS csv2 zone files without the tilde character are
compatible with the updated csv2 parser, unless csv2_tilde_handling is
set to 3. All older MaraDNS csv2 zone files will parse in MaraDNS if
csv2_tilde_handling has a value of 0. Older MaraDNS releases also
supported the csv2_tilde_handling variable (as long as it had a value
of 0); this allowed the same configuration and zone files to be used in
older and newer MaraDNS releases.
Resourcerecordformat
This zone file format has records in the following form:
name [+ttl] [rtype] rdata ~
The name is the name of the record we will add, such as
"www.example.net.". This must be placed at the beginning of a line.
The rtype is the record type for the record, such as "A" (ipv4 IP
address), "MX" (mail exchanger), or "AAAA" (ipv6 IP address). The ttl
is how long other DNS servers should store this data in their memory
(in seconds); this field needs a '+' as its initial character. The
rdata is the actual data for this record; the format for the rdata is
type-specific.
Anything in square brackets is an optional field. If the ttl is not
specified, the ttl is set to the default ttl value (see "Default TTL"
below). If the rtype is not specified, it is set to be an "A" (ipv4
address) record.
The zone file supports comments; comments are specified by having a '#'
anywhere between fields or records; when a '#' is seen, the csv2 parser
ignores any character it sees (with the exception of the '{', which is
not allowed in comments) until a newline. A '#' can usually be placed
inside a field, and indicates the end of a field when placed there.
A '{' character can never be placed in a comment. A '~' character is
always allowed in a comment, and has no special meaning when placed in
a comment.
The following record types are supported; a description of the record
data format accommodates the record type:
A
An A record stores an ipv4 address. This is the default record type
should the record type not be specified. The record type has one field
in it: the IP for the record. Examples:
a.example.net. 10.11.12.13 ~
b.example.net. A 10.11.12.14 ~
c.example.net. +64000 A 10.11.12.15 ~
PTR
A PTR record stores the name for a given ipv4 or ipv6 address, and is
used for reverse DNS lookups. This record type has one field in it: The
name for the record in question. Examples:
13.12.11.10.in-addr.arpa. PTR a.example.net. ~
14.12.11.10.in-addr.arpa. PTR b.example.net. ~
15.12.11.10.in-addr.arpa. +64000 PTR c.example.net. ~
MX
A MX record stores a mail exchange record, and is used for mail
delivery. This record type has two fields in it: The priority (or
"preference" in traditional DNS parlance) of the MX record (lower
numbers get higher priority), and the name of the mail exchanger.
Example of mail for example.net being mailed to mail.example.net, which
has the IP "10.11.12.16":
example.net. MX 10 mail.example.net. ~
mail.example.net. 10.11.12.16 ~
AAAA
An AAAA record stores the ipv6 address for a given name. The IP is in
standard ipv6 "colon delimited" format: eight 16-bit hexadecimal
numbers are separated by colons. Two colons together indicate multiple
streams of all-zero hex numbers. This record has only one field, the v6
IP. Example:
a.example.net. AAAA 3ffe:ffff:ffe:501:ffff::b:c:d ~
SRV
An SRV record stores a "service" definition. This record has four
fields: Priority, weight, port, and target. For more information,
please refer to RFC 2782. Example:
_http._tcp.% SRV 0 0 80 a.% ~
NS
An NS record specifies the name servers for a given zone. If the name
servers are not delegation name servers (in other words, if the name
servers are the authoritative name servers for the zone), they need to
be at the beginning of the zone, either as the first records in the
zone, or right after the SOA record. The NS records are optional; if
not present, MaraDNS will make an educated guess of that NS records
should be there, based on the IPs the MaraDNS process is bound to. This
record has one field: The name of the name server machine. Example:
example.net. NS ns1.example.net. ~
example.net. NS ns2.example.net. ~
SOA
An SOA record stores the start of authority for a given zone file.
This record is optional in a CSV2 zone file; should the record not be
in the zone file, MaraDNS will synthesize an appropriate SOA record.
This record can only exist once in a zone file: As the first record of
the zone file. This record has seven fields: The name of the zone, the
email address of the person responsible for the zone, and five numeric
fields (serial, refresh, retry, expire, and minimum). Note that the
SOA minimum does not affect other TTLs in MaraDNS. Example:
x.org. SOA x.org. email@x.org. 1 7200 3600 604800 1800 ~
The serial numeric field may be replaced by the string '/serial'; this
string tells the CSV2 zone parser to synthesize a serial number for the
zone based on the timestamp for the zone file. This allows one to have
the serial number be automatically updated whenever the zone file is
edited. Here is how this special field looks in a SOA record:
x.org. SOA x.org. email@x.org. /serial 7200 3600 604800 1800 ~
The '/serial' string is case-sensitive; only '/serial' in all lower
case will parse.
TXT
A TXT record stores arbitrary text and/or binary data for a given host
name. This record has one field: The text data for the record.
A basic text record can be stored by placing ASCII data between two
single quotes, as follows:
example.com. TXT 'This is an example text field' ~
Any binary data can be specified; see the csv2_txt(5) manual page for
full details.
If tildes are used to separate records, a TXT record can not contain a
'|' (pipe) character, a '#' character, nor any ASCII control character;
these characters can be added to a TXT record via the use of escape
sequences; read the csv2_txt man page for details.
SPF
A SPF record is, with the exception of the numeric rtype, identical to
a TXT record. SPF records are designed to make it more difficult to
forge email. More information about SPF records can be found in
RFC4408, or by performing a web search for 'sender policy framework'.
RAW
The RAW record is a special meta-record that allows any otherwise
unsupported record type to be stored in a csv2 zone file. The syntax
is:
RAW [numeric rtype] [data] ~
The numeric rtype is a decimal number.
The data field can, among other thing, have backslashed hex sequences
outside of quotes, concatenated by ASCII data inside quotes, such as
the following example:
example.com. RAW 40 \x10\x01\x02'Kitchen sink'\x40' data' ~
The above example is a "Kitchen Sink" RR with a "meaning" of 16, a
"coding" of 1, a "subcoding" of 2, and a data string of "Kitchen sink@
data" (since hex code 40 corresponds to a @ in ASCII). Note that
unquoted hex sequences are concatenated with quoted ASCII data, and
that spaces are only inside quoted data.
The format for a data field in a RAW record is almost identical to the
format for a TXT data field. Both formats are described in full in the
csv2_txt(5) manual page.
FQDN4
The FQDN4 (short for "Fully Qualified Domain Name for IPv4") record is
a special form of the "A" record (see above) that instructs MaraDNS to
automatically create the corresponding PTR record. For example, the
following is one way of setting up the reverse DNS lookup for
x.example.net:
x.example.net. A 10.3.28.79 ~
79.28.3.10.in-addr.arpa. PTR x.example.net. ~
But the above two lines in a zone file can also be represented thusly:
x.example.net. FQDN4 10.3.28.79 ~
Note that the csv2 parser does not bother to check that any given IP
only has a single FQDN4 record; it is up to the DNS administrator to
ensure that a given IP has only one FQDN4 record. In the case of there
being multiple FQDN4 records with the same IP, MaraDNS will have
multiple entries in the corresponding PTR record, which is usually not
the desired behavior.
FQDN4 records are not permitted in a csv2_default_zonefile. If you do
not know what a csv2_default_zonefile is, you do not have to worry
about this limitation.
FQDN6
The FQDN6 (short for "Fully Qualified Domain Name for IPv6") record is
the ipv6 form for the FQDN4 record. Like the FQDN4 record, this record
creates both a "forward" and "reverse" DNS record for a given host
name. For example, onoe may have:
x.example.net. AAAA 3ffe:ffff:ffe:501:ffff::b:c:d ~
d.0.0.0.c.0.0.0.b.0.0.0.f.f.f.f.1.0.5.0.e.f.f.0.f.f.f.f.e.f.f.3 PTR
x.example.net. ~
But the above two lines in a zone file can also be represented thusly:
x.example.net. FQDN6 3ffe:ffff:ffe:501:ffff::b:c:d ~
Like FQDN4 records, it is the DNS administrator's duty to make sure
only a single IP has a FQDN6 record.
FQDN6 records are, like FQDN6 records, not permitted in a
csv2_default_zonefile. If you do not know what a csv2_default_zonefile
is, you do not have to worry about this limitation.
FQDN6 records were implemented by Jean-Jacques Sarto.
CNAME
A CNAME record is a pointer to another host name. The CNAME record, in
MaraDNS, affects any record type not already specified for a given host
name. While MaraDNS allows CNAME and non-CNAME records to share the
same host name, this is considered bad practice and is not compatible
with some other DNS servers.
CNAME records are not permitted in a csv2_default_zonefile. If you do
not know what a csv2_default_zonefile is, this fact is of no relevance.

Historicalanduncommonresourcerecords

The following resource records are mainly of historical interest, or
are not commonly used.
HINFO
An HINFO record is a description of the CPU (processor) and OS that a
given host is using. The format for this record is identical to a TXT
record, except that the field must have precisely two chunks.
The first chunk of a HINFO record is the CPU the host is running; the
second chunk is the OS the host is running.
Example:
example.com. HINFO 'Intel Pentium III';'CentOS Linux 3.7' ~
This resource record is not actively used--the IANA has a list of CPUs
and OSes that this record is supposed to have. However, this list has
not been updated since 2002.
WKS
WKS records are historical records which have been superseded by SRV
records. The format of the record is an IP, followed by a protocol
number (6 means TCP), followed by a list of ports that a given server
has available for services.
For example, to advertise that example.net has the IP 10.1.2.3, and has
a SSH, HTTP (web), and NNTP server:
example.net. WKS 10.1.2.3 6 22,80,119 ~
MaraDNS only allows up to 10 different port numbers in a WKS record,
and requires that the listed port numbers are not be higher than 1023.
MDandMF
MD and MF records are RR types that existed before MX records, and were
made obsolete by MX records. RFC1035 says that a DNS server can either
reject these records or convert these records in to MX records. BIND
rejects these records; MaraDNS converts them.
Example:
example.net. MD a.example.net. ~
example.net. MF b.example.net. ~
Is equivalent to:
example.net. MX 0 a.example.net. ~
example.net. MX 10 b.example.net. ~
MB,MG,MINFO,andMR
In the late 1980s, an alternative to MX records was proposed. This
alternative utilized MB, MG, MINFO, and MR records. This alternative
failed to gather popularity. However, these records were codified in
RFC1035, and are supported by MaraDNS. Here is what the records look
like:
example.net. MB mail.example.net. ~
example.net. MG mg@example.net. ~
example.net. MINFO rm@example.net. re@example.net. ~
example.net. MR mr@example.net. ~
More information about these records can be found in RFC1035.
AFSDB,RP,X25,ISDN,andRT
AFSDB, RP, X25, ISDN, and RT are resource records which were proposed
in RFC1183. None of these resource records are widely used.
With the exception of the ISDN record, the format of these records is
identical to the examples in RFC1183. The format of the ISDN record is
identical unless the record has a subaddress (SA). If an ISDN record
has a subaddress, it is separated from the ISDN-address by a ';'
instead of whitespace.
If used, here is how the records would look in a csv2 zone file:
example.net. AFSDB 1 afsdb.example.net. ~
example.net. RP rp@example.net. rp.example.net. ~
example.net. RP rp2@example.net. . ~
example.net. X25 311061700956 ~
example.net. ISDN 150862028003217 ~
example.net. ISDN 150862028003217;004 ~
example.net. RT 10 relay.example.net. ~
NSAPandNSAP-PTR
NSAP and NSAP-PTR records were proposed in RFC1706. A NSAP record is a
hexadecimal number preceded by the string "0x" and with optional dots
between bytes. This hexadecimal number is converted in to a binary
number by MaraDNS. A NSAP-PTR record is identical to a PTR record, but
has a different RTYPE.
More information about these records can be obtained from RFC1706.
If used, here is how the records would look in a csv2 zone file:
example.net. NSAP 0x47.0005.80.005a00.0000.0001.e133.ffffff000162.00 ~
example.net. NSAP-PTR nsap.example.net. ~
PX
The PX RR is an obscure RR described in RFC2163. A PX record looks like
this in a CSV2 zone file:
example.net. PX 15 px1.example.net. px2.example.net. ~
GPOS
An GPOS record is a description of the location of a given server. The
format for this record is identical to a TXT record, except that the
field must have precisely three chunks.
The first chunk of a GPOS record is the longitude; the second chunk is
the latitude; the third chunk is the altitude (in meters).
Example:
example.net. GPOS '-98.6502';'19.283';'2134' ~
More information about this record can be found in RFC1712.
This resource record is not actively used; for the relatively few
people who encode their position in DNS, the LOC record is far more
common.
LOC
The LOC resource record is an uncommonly used resource record that
describes the position of a given server. LOC records are described in
RFC1876.
Note that MaraDNS' LOC parser assumes that the altitude, size,
horizontal, and vertical precision numbers are always expressed in
meters. Also note that that sub-meter values for size, horizontal, and
vertical precision are not allowed. Additionally, the altitude can not
be greater than 21374836.47 meters.
Example:
example.net. LOC 19 31 2.123 N 98 3 4 W 2000m 2m 4m 567m ~

SLASHCOMMANDS

In addition to being able to have resource records and comments, csv2
zone files can also have special slash commands. These slash commands,
with the exception of the '/serial' slash command (see "SOA" above),
can only be placed where the name for a record would be placed. Like
resource records, a tilde is to be placed after the slash command. Note
also that slash commands are case-sensitive, and the command in
question must be in all-lower-case.
These commands are as follows:
DefaultTTL
The default TTL is the TTL for a resource record without a TTL
specified. This can be changed with the '/ttl' slash command. This
command takes only a single argument: The time, in seconds, for the new
default TTL. The '/ttl' slash command only affects the TTL of records
that follow the command. A zone file can have multiple '/ttl' slash
commands.
The default TTL is 86400 seconds (one day) until changed by the '/ttl'
slash command.
In the following example, a.ttl.example.com will have a TTL of 86400
seconds (as long as the zone file with this record has not previously
used the '/ttl' slash command), b.ttl.example.com and d.ttl.example.com
will have a TTL of 3600 seconds, c.ttl.example.com will have a TTL of
9600 seconds, and e.ttl.example.com will have a TTL of 7200 seconds:
a.ttl.example.com. 10.0.0.1 ~
/ttl 3600 ~
b.ttl.example.com. 10.0.0.2 ~
c.ttl.example.com. +9600 10.0.0.3 ~
d.ttl.example.com. 10.0.0.4 ~
/ttl 7200 ~
e.ttl.example.com. 10.0.0.5 ~
Origin
It is possible to change the host name suffix that is used to
substitute the percent in a csv2 zone file. This suffix is called, for
historical and compatibility reasons, "origin". This is done as the
slash command '/origin', taking the new origin as the one argument to
this function. Note that changing the origin does not change the
domain suffix used to determine whether a given domain name is
authoritative.
Here is one example usage of the '/origin' slash command:
/origin example.com. ~
www.% 10.1.0.1 ~
% MX 10 mail.% ~
mail.% 10.1.0.2 ~
/origin example.org. ~
www.% 10.2.0.1 ~
% MX 10 mail.% ~
mail.% 10.2.0.2 ~
Which is equivalent to:
www.example.com. 10.1.0.1 ~
example.com. MX 10 mail.example.com. ~
mail.example.com. 10.1.0.2 ~
www.example.org. 10.2.0.1 ~
example.org. MX 10 mail.example.org. ~
mail.example.org. 10.2.0.2 ~
It is also possible to make the current origin be part of the new
origin:
/origin example.com. ~
% 10.3.2.1 ~ # example.com now has IP 10.3.2.1
/origin mail.% ~
% 10.3.2.2 ~ # mail.example.com now has IP 10.3.2.2
OpushandOpop
The '/opush' and '/opop' slash commands use a stack to remember and
later recall values for the origin (see origin above). The '/opush'
command is used just like the '/origin' command; however, the current
origin is placed on a stack instead of discarded. The '/opop' command
removes ("pops") the top element from this stack and makes the element
the origin.
For example:
/origin example.com. ~
/opush mail.% ~ # origin is now mail.example.com; example.com is on stack
a.% 10.4.0.1 ~ # a.mail.example.com has IP 10.4.0.1
/opush web.example.com. ~ # mail.example.com and example.com are on stack
a.% 10.5.0.1 ~ # a.web.example.com has IP 10.5.0.1
b.% 10.5.0.2 ~ # b.web.example.com has IP 10.5.0.2
/opop ~ # origin is now mail.example.com again
b.% 10.4.0.2 ~ # b.mail.example.com has IP 10.4.0.2
/opop ~ # origin is now example.com
% MX 10 a.mail.% ~ # example.com. MX 10 a.mail.example.com.
% MX 20 b.mail.% ~ # example.com. MX 20 b.mail.example.com.
The opush/opop stack can have up to seven elements on it.
Read
The '/read' slash commands allows one to have the contents of another
file in a zone. The '/read' command takes a single argument: A filename
that one wishes to read. The filename is only allowed to have letters,
numbers, the '-' character, the '_' character, and the '.' character in
it.
The file needs to be in the same directory as the zone file. The file
will be read with the same privileges as the zone file; content in the
file should come from a trusted source or be controlled by the system
administrator.
Let us suppose that we have the following in a zone file:
mail.foo.example.com. 10.3.2.1 ~
/read foo ~
foo.example.com. MX 10 mail.foo.example.com. ~
And a file foo with the following contents:
foo.example.com. 10.1.2.3 ~
foo.example.com. TXT 'Foomatic!' ~
Then foo.example.com will have an A record with the value 10.1.2.3, a
TXT value of 'Foomatic!', and a MX record with priority 10 pointing to
mail.foo.example.com. mail.foo.example.com will have the IP 10.3.2.1.
Note that no pre-processing nor post-processing of the origin is done
by the '/read' command; should the file read change the origin, this
changed value will affect any records after the '/read' command. For
example, let us suppose db.example.com looks like this:
/origin foo.example.com. ~
% TXT 'Foomatic!' ~
/read foo ~
% MX 10 mail.foo.example.com. ~
And the file foo looks like this:
% 10.1.2.3 ~
/origin mail.% ~
% 10.3.2.1 ~
Then the following records will be created:
foo.example.com. TXT 'Foomatic!' ~
foo.example.com. A 10.1.2.3 ~
mail.foo.example.com. A 10.3.2.1 ~
mail.foo.example.com. MX 10 mail.foo.example.com. ~
To have something that works like '$INCLUDE filename' in a RFC1035
master file, do the following:
/opush % ~
/read filename ~
/opop ~
Or, for that matter, the equivalent of '$INCLUDE filename neworigin':
/opush neworigin. ~
/read filename ~
/opop ~

EXAMPLEZONEFILE

# This is an example csv2 zone file
# First of all, csv2 zone files do not need an SOA record; however, if
# one is provided, we will make it the SOA record for our zone
# The SOA record needs to be the first record in the zone if provided
# This is a commented out record and disabled.
#% SOA % email@% 1 7200 3600 604800 1800 ~
# Second of all, csv2 zone files do not need authoritative NS records.
# If they aren't there, MaraDNS will synthesize them, based on the IP
# addresses MaraDNS is bound to. (She's pretty smart about this; if
# Mara is bound to both public and private IPs, only the public IPs will
# be synthesized as NS records)
#% NS a.% ~
#% NS b.% ~
# Here are some A (ipv4 address) records; since this is the most
# common field, the zone file format allows a compact representation
# of it.
a.example.net. 10.10.10.10 ~
# Here, you can see that a single name, "b.example.net." has multiple IPs
# This can be used as a primitive form of load balancing; MaraDNS will
# rotate the IPs so that first IP seen by a DNS client changes every time
# a query for "b.example.net." is made
b.example.net. 10.10.10.11 ~
b.example.net. 10.10.10.12 ~
# We can have the label in either case; it makes no difference
Z.EXAMPLE.NET. 10.2.3.4 ~
Y.EXAMPLE.net. 10.3.4.5 ~
# We can use the percent shortcut. When the percent shortcut is present,
# it indicates that the name in question should terminate with the name
# of the zone we are processing.
percent.% a 10.9.8.7 ~
# And we can have star records
#*.example.net. A 10.11.12.13 ~
# We can have a ttl in a record; however the ttl needs a '+' before it:
# Note that the ttl has to be in seconds, and is before the RTYPE
d.example.net. +86400 A 10.11.12.13 ~
f.example.net. # As you can see, records can span multiple lines
A 10.2.19.83 ~
# This allows well-commented records, like this:
c.example.net. # Our C class machine
+86400 # This record is stored for one day
A # A record
10.1.1.1 # Where we are
~ # End of record
# We can even have something similar to csv1 if we want...
e.example.net.|+86400|a|10.2.3.4|~
h.example.net.|a|10.9.8.7|~
# Here, we see we can specify the ttl but not the rtype if desired
g.example.net.|+86400|10.11.9.8|~
# Here is a MX record
% mx 10 mail.% ~
mail.% +86400 IN A 10.22.23.24 ~
# We even have a bit of ipv6 support
a.example.net. aaaa 3ffe:ffff:1:2:3::4:f ~
# Not to mention support for SRV records
_http._tcp.% srv 0 0 80 a.% ~
# TXT records, naturally
example.net. txt 'This is some text' ~
# Starting with MaraDNS 1.2.08, there is also support for SPF records,
# which are identical to TXT records. See RFC4408 for more details.
example.net. spf 'v=spf1 +mx a:colo.example.com/28 -all' ~

LEGALDISCLAIMER

THIS SOFTWARE IS PROVIDED BY THE AUTHORS ''AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.